DAYS 1-5 (JULY 21-25)
We know that low pressure areas can bring us a variety of weather. However, high pressure areas can do the same, in their own way, and the next 5 days will provide an example of that. It may not sound like it when I first say that high pressure will bring us fair weather today into Friday, until a cold front approaches and brings a shot at showers and thunderstorms later Friday. Fair weather is fair weather, but the differences are in wind direction / speed, air temperature, and dew point, based on the position of the high pressure area, and this is a big factor in how it feels. So how does that change during these days? Today, with the high center in the northern Great Lakes, the flow between it and eastern Canadian low pressure will deliver a cool, dry, Canadian air mass on a gusty northwesterly breeze. One note though: Usually on days like this week think of a cobalt blue sky to go with the pleasant air mass, but you’ll notice a bit of a hazy look instead, and this is due to a plume of wildfire smoke aloft from Canada. Tuesday, as the high center builds from the Great Lakes into New England, we’ll see the northwesterly breeze fade away, and much lighter wind which will then allow a coastal sea breeze to develops. Wednesday, the high center starts to move offshore to our east and southeast, so a cool and calm Tuesday night after the sea breeze collapses will be replaced with a light southerly air flow and the first up-tick in the humidity after two very dry days. The air temperature will also rise a little, with some areas breaking 80 after two days in the 70s. This day, the “coolest” air would be at the South Coast due to the southerly wind flow being directly off the ocean water, which does run slightly cooler than what the land will warm up to during the day. Thursday and Friday, high pressure will remain offshore to the southeast and pump in increasing amounts of heat and humidity, peaking on Friday ahead of the aforementioned cold front. So there is how the weather changes from one “fair weather” system during the course of several days. Still, it’s a pretty decent vacation week in the region if it’s the one you picked and you’re hanging around here, or visiting here from elsewhere. Enjoy!
TODAY: Thin smoke aloft, otherwise sunshine with some passing clouds. Highs 72-79. Dew point falls through the 50s. Wind NW 5-15 MPH, gusty.
TONIGHT: Mostly clear. Lows 51-58. Dew point below 50. Wind NW diminishing to under 10 MPH.
TUESDAY: Sunny. Highs 71-78, coolest in coastal areas. Dew point below 50. Wind variable up to 10 MPH with coastal sea breezes.
TUESDAY NIGHT: Clear. Patchy ground fog inland low elevations. Lows 48-55. Dew point below 50. Wind calm.
WEDNESDAY: Sunny. Highs 78-85, coolest Cape Cod / South Coast. Dew point rising through 50s to around 60. Wind S up to 10 MPH.
WEDNESDAY NIGHT: Mostly clear. Patchy fog interior low elevations. Lows 61-68. Dew point near 60. Wind S to SW under 10 MPH.
THURSDAY: Mostly sunny. Highs 78-85 South Coast, 85-92 elsewhere. Dew point in 60s. Wind SW 5-15 MPH.
THURSDAY NIGHT: Mostly clear. Lows 68-75. Dew point rises toward 70. Wind SW up to 10 MPH.
FRIDAY: Sunshine through midday. Clouds develop / arrive later in the day with a chance of showers and thunderstorms. Highs 88-95 except cooler South Coast / Cape Cod. Dew point 70+. Wind SW 10-20 MPH.
DAYS 6-10 (JULY 26-30)
There’s some uncertainty on the weekend forecast (July 26-27) based on the movement / positioning of the front that comes into our region later Friday. How I think it plays out is the front is still near the South Coast into Saturday with a shower and thunderstorm threat lingering in southern areas with fair weather to the north, and then the front lifts slowly back to the north with the help of an approaching disturbance from the west Sunday with eventually a better chance of showers and thunderstorms. Beyond that, timing of the disturbance would determine the July 28 weather – possibly with the disturbance slow enough for additional showers and storms, then fair weather following that toward the middle of next week.
DAYS 11-15 (JULY 31 – AUGUST 4)
Overall pattern indications a west to northwest flow east of a central US high pressure ridge with a trough of low pressure in Atlantic Canada. Shower/thunderstorm chances would be limited to a couple passing disturbances and most of the time the region would see fair weather, with somewhat variable temperatures but no sustained heat.